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1
Lamb, J. F. S., L. D. Johnson, D. K. Barnes, and J. J. Marquez-Ortiz. "A method to characterize root morphology traits in alfalfa." Canadian Journal of Plant Science 80, no. 1 (January 1, 2000): 97–104. http://dx.doi.org/10.4141/p98-124.
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Productivity in alfalfa (Medicago sativa L.) has been shown to be influenced by root morphology. Our objectives were to identify the optimum age, cultural practices, and environmental conditions to characterize taproot diameter (TD), lateral root number (LRN), fibrous root mass (FRM), and determinate taproot percentage (DTP) in alfalfa. No correlations were found between greenhouse-cultured plants and 21-wk-old field-grown plants for LRN or FRM, while TD showed low to moderate correlations between greenhouse and field environments. Fourfold more plants with determinate taproots were identified in transplanted plots compared to seeded plots. All root traits were affected by plant spacing but, no germplasm × plant spacing interactions were found. Solid seeded plants needed more time to show maximum expression of root traits and scored lower for LRN and FRM and had smaller TD than spaced plants. Only TD had a significant germplasm × location interaction. Both TD and LRN increased with N fertilizer and between the seeding and first production years, but no germplasm × N rate or germplasm × year interactions were found. Rankings of alfalfa germplasms were the same at the end of the seeding year (22 wk after planting) and at the end of the first production year (74 wk after planting). Characterization of LRN and FRM in alfalfa should be conducted in seeded field plots with uniform plant spacing at one location, with or without N fertilizer at least 22 wk after planting. A similar protocol with evaluation at more than one location would be more appropriate for characterization of TD. Key words: Medicago sativa L., root morphology, alfalfa
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Benny, Gerald L. "Classical morphology in zygomycete taxonomy." Canadian Journal of Botany 73, S1 (December 31, 1995): 725–30. http://dx.doi.org/10.1139/b95-315.
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Classification of Zygomycetes has evolved with the description of new taxa and the rediscovery and redescription of known species. Taxonomy of orders in Zygomycetes is based on the morphology of the spore forming structures, sporangia and (or) sporangiola, or merosporangia. Some organisms produce only zygospores, azygospores, chlamydospores, or a combination of these structures. The occurrence and morphology of any of the aforementioned structures and others (e.g., stolons and rhizoids, apophyses, branching pattern, fertile vesicles) are used to ascertain the phylogenetic relationships in Mucorales. Our understanding of the morphology, development, and phylogeny of Zygomycetes has been enhanced by using microscopic observations and cladistic analysis of data sets derived both from small subunit rDNA and morphology. Many morphological characters (e.g., trophocyst, yeast cell formation) still appear to be reliable phylogenetic indicators while others (e.g., spore morphology) are too variable. The value of zygospore morphology is reduced because the sexual spore has never been reported for many taxa. Many characters used to circumscribe mucoralean families probably do not indicate relationships but still are useful in identification. Sporangiola should be considered indistinct from sporangia. Key words: cladistics, morphology, Mucorales, phylogeny, sporangia, sporangiola.
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Castellani, C. "Seasonal variation in egg morphology and hatching success in the calanoid copepods Temora longicornis, Acartia clausi and Centropages hamatus." Journal of Plankton Research 25, no. 5 (May 1, 2003): 527–37. http://dx.doi.org/10.1093/plankt/25.5.527.
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Hesp, Patrick A. "A review of biological and geomorphological processes involved in the initiation and development of incipient foredunes." Proceedings of the Royal Society of Edinburgh. Section B. Biological Sciences 96 (1989): 181–201. http://dx.doi.org/10.1017/s0269727000010927.
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SynopsisThe evolution, ecological processes, aerodynamics, and morphology of incipient or new foredunes on the upper beach is reviewed. Four types of incipient foredunes may be distinguished, namely: type 1, those initiated by shadow dune formation within zones of discrete individual pioneer annuals (e.g. Cakile spp.), and perennials (e.g. Spinifex spp.; Ammophila spp.); type 2, those initiated by dunelet or hummock formation within discrete colonies of perennial grasses and herbs; type 3, those initiated by sand deposition within laterally extensive colonies of pioneer seedlings; and type 4, those initiated by sand deposition within a laterally extensive plant rhizome cover.Type 1 dunes are dominated by high, local flow deceleration and 3-D flow separation. Shadow dunes form within and downwind of the discrete plants. If colonised by annual plants, invasion by perennial plants is necessary for survival. Later lateral plant spread and accretion produces hummocky terraces and ridges. Type 2 dunes (dunelets) are characterised by local landward flow deceleration and marginal high velocity side flows. Sand deposition results in the formation of low, discrete, semi-circular convex mounds (seedlings), or more elongate hummocks and mounds (rhizomes). Types 3 and 4 dunes are characterised by laterally extensive, often homogeneous vegetation canopies. High canopies display more rapid landward flow deceleration than low canopies, thus narrow, asymmetric ridges and longer convex ridges result respectively. High plant densities result in rapid down-canopy flow deceleration, maximum traction load retardation and the formation of narrow asymmetric ridges. Dune height decreases and dune length increases as plant densities decrease. Maximum deposition zones occur for each wind velocity range. Whether ramp, terrace or ridge morphologies are formed depends on mode of beach colonisation, plant density and distribution, sand volume, wind speed, and plant species type and morphology.A range of variables which affect foredune morphology and evolution, including plant canopy density, height and distribution, wind velocity, and various ecological environmental processes are examined.
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Flint, Hollis M., Joseph E. Leggett, LeAnne Elhoff, Nancy J. Parks, and Elizabeth W. Davidson. "Effects of the Plant Growth Regulator Mepiquat Chloride on Silverleaf Whitefly (Homoptera: Aleyrodidae) Infestations on Cotton2." Journal of Entomological Science 31, no. 1 (January 1, 1996): 112–22. http://dx.doi.org/10.18474/0749-8004-31.1.112.
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Cotton, Gossypium hirsutum L., plants were treated with the plant growth regulator mepiquat chloride (Pix™) in greenhouse and field plot tests to determine its effect on infestations of the silverleaf whitefly, Bemisia argentifolii Bellows and Perring. In the greenhouse, Pix-treated plants were significantly shorter and had thicker leaves than untreated plants by the end of the second week following application. Most of the Pix treatments caused significant reductions in adults, eggs and nymphs on leaves by fourth and final week of the test. In a separate test, leaf water potentials were equal for Pix-treated and well-watered plants which were significantly lower than for water-stressed and control plants. Pix-treated plants in two field plot tests showed the same changes in plant morphology observed in Pix-treated plants in the greenhouse. However, leaf water potentials were the same as in untreated plants and no reductions in whitefly infestations were found during the 6 to 7 wk test periods. Pix-treated plants in a third field plot test showed no changes in plant morphology or in whitefly infestations. The reduced whitefly infestations of Pix-treated plants in the greenhouse, but not in field plots, may have been due to reduced leaf water potentials in Pix-treated greenhouse plants but not in field plants.
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Stolter, C., John P. Ball, and R. Julkunen-Tiitto. "Seasonal differences in the relative importance of specific phenolics and twig morphology result in contrasting patterns of foraging by a generalist herbivore." Canadian Journal of Zoology 91, no. 5 (May 2013): 338–47. http://dx.doi.org/10.1139/cjz-2012-0270.
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The co-evolved relationship between the chemical composition of plants and herbivory is fundamental in understanding diet selection of herbivores and their impacts on plants and ecosystems. However, the impact of plant secondary chemistry on mammalian herbivory is not fully understood. We investigated seasonal influences of phenolics with low molecular weight (e.g., flavonoids, salicylates) and plant morphology of the tea-leaved willow (Salix phylicifolia L.) on moose (Alces alces (L., 1758)) foraging. We analysed the relationship of different phenolic compounds in twigs and browsing in winter, and in leaves and the degree of leaf stripping in summer, and the role of plant morphology. In winter, higher concentrations of phenolics, e.g., myricetin-related compounds (belonging to the flavonoids), had a negative impact on herbivory by moose. This impact was not associated with a single compound but instead seemed to be more a result of synergistic or additive effects of different compounds. In contrast, the models for summer browsing showed a pronounced effect of plant morphology. Our analyses reveal differences in the relative importance of phenolics of low molecular weight and plant morphology on diet selection between seasons. These findings are relevant for understanding feeding decisions and mechanisms deterring mammalian herbivores known for shaping the vegetation on the ecosystem level.
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Rajapakse, Nihal C., Margaret J. McMahon, and John W. Kelly. "INFLUENCE OF END OF DAY FAR-RED LIGHT ON HEIGHT OF CHRYSANTHEMUM PLANTS UNDER CuSO4 SPECTRAL FILTERS." HortScience 27, no. 6 (June 1992): 649a—649. http://dx.doi.org/10.21273/hortsci.27.6.649a.
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The response of `Bright Golden Anne' and `Spears' chrysanthemum plants to EOD-R or FR light was evaluated to determine the involvement of phytochrome in regulation of plant morphology under CuSO4 filters. Light transmitted through the CuSO4 filter significantly reduced height, internode length and stem dry weight of `BGA' and `Spears' chrysanthemum plants. However, the degree of response varied with the cultivar. Exposure to EOD-FR reversed the reduction of plant height, internode length and the stem dry weight caused by the light transmitted through CuSO4 filters to a level comparable with control plants. Exposure to EOD-FR did not significantly alter height and stem dry weight under control filter Exposure to EOD-R light reduced the height and stem dry weight of `BGA' plants grown under control filter but EOD-R had no effect under CuSO4 filters. In `Spears' plants, EOD-R caused stem dry weight reduction under control filters, but did not reduce stem or internode elongation. The results suggest phytochrome may be involved in controlling plant response under CuSO4 filters. However, there are evidence to indicate that an additional mechanism may be acting on stem/internode elongation.
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Neubig, Kurt M., and J. Richard Abbott. "Interspecific hybridization in North American Polygala (Polygalaceae)." Journal of the Botanical Research Institute of Texas 14, no. 1 (July 15, 2020): 47–56. http://dx.doi.org/10.17348/jbrit.v14.i1.895.
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As a part of ongoing systematic and phylogenetic studies in Polygalaceae, field collections of two pairs of North American species (Polygala balduinii and P. ramosa, and P. lutea and P. rugelii) had morphologically intermediate forms and grew sympatrically, and so were suspected to be interspecific hybrids. Although hybrids among plants are often invoked in taxonomic and floristic literature based on morphologic intermediacy, they are rarely documented and substantiated using molecular tools. We found that the morphologically intermediate individuals within intermixed populations of both species pairs did indeed share all of the variable nucleotide sites in nrITS among the parent species. Likewise, using plastid sequence data (trnL-F), we determined that in both species pairs, the parentage was bidirectional. Although some DNA inheritance phenomena (e.g. incomplete lineage sorting) can result in similar polymorphic DNA sequence data, the intermediacy in both morphology and sequence data within sympatric populations is more indicative of interspecific hybridization.
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McLaughlin, D. J., M. E. Berres, and L. J. Szabo. "Molecules and morphology in basidiomycete phylogeny." Canadian Journal of Botany 73, S1 (December 31, 1995): 684–92. http://dx.doi.org/10.1139/b95-311.
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To obtain an understanding of the relationships of the basidiomycetes, especially those with horizontally partitioned metabasidia, and of the evolution of structural characters, members of nine orders and an additional four genera of simple-septate fungi (Auriculariales sensu lato) were studied using cladistic analysis of light microscopic and ultrastructural characters. Comparisons were made with the nucleotide sequence from the 5′ end of the nuclear large subunit ribosomal RNA gene analyzed with several algorithms, including parsimony and maximum likelihood. Analyses of both morphological and molecular characters support similar phylogenetic conclusions, but polarization of some morphological characters was difficult without guidance from molecular data. The Uredinales are shown to be an advanced taxon arising from the simple-septate Auriculariales sensu lato, and some characters that they share with the ascomycetes result from convergent evolution. The simple-septate Auriculariales consists of more than one clade, and the related gasteroid Pachnocybe ferruginea possesses numerous derived light microscopic characters, including holobasidia. Key words: basidiomycetes, character evolution, cladistics, molecular evolution, phylogeny.
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Barten, J. H. M., J. W. Scott, and R. G. Gardner. "Characterization of Blossom-end Morphology Genes in Tomato and Their Usefulness in Breeding for Smooth Blossom-end Scars." Journal of the American Society for Horticultural Science 119, no. 4 (July 1994): 798–803. http://dx.doi.org/10.21273/jashs.119.4.798.
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Pointed blossom-end morphology may be used to reduce blossom-end scar size in large-fruited, fresh-market tomatoes (Lycopersicon esculentum Mill.). The usefulness of this characteristic has been limited due to persistence of pointedness on mature fruit, resulting in postharvest bruising, and to close association of pointedness with leaf curl, which may increase foliar disease problems. The inheritance of pointedness in three breeding lines (NC 140, Fla 890559-24, and Fla 894413-1) and four accessions with previously described blossom-end morphology genes [LA 2-5 with persistent style (pst), LA 986 with beaky (bk), LA 1787 with beaky-2 (Bk-2), and LA 2353 with nipple tip (n)] was investigated. In F1 s and F2s of crosses with wild types, some pointedness was observed in heterozygotes, but the level of expression was generally close to wild type expression, except for LA 986. Consequently, Bk-2 in LA 1787 was renamed bk-2. F1 complementation tests were difficult to interpret. Wild types segregated in F2s of all complementation crosses, except for LA 986 × LA 2-5, a result indicating the presence of the same gene in these two accessions. Three new nipple-tip genes were named; n-2 in NC 140, n-3 in Fla 890559-24, and n-4 in Fla 894413-1. None of the seven accessions tested had significant leaf curl. Early identification of mutant plants by the shape of the stylar base in flowers at anthesis was reliable only for bk. Various blossom-end morphology genes may be backcrossed into otherwise desirable breeding lines, and complementing parents may be intercrossed to obtain optimal smoothness in the hybrid without undesirable pointed mature hybrid fruit.
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Rutishauser, Rolf. "Developmental patterns of leaves in Podostemaceae compared with more typical flowering plants: saltational evolution and fuzzy morphology." Canadian Journal of Botany 73, no. 9 (September 1, 1995): 1305–17. http://dx.doi.org/10.1139/b95-142.
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Leaves and stems of flowering plants have been widely accepted as clearly distinguishable structural categories. Evolution, however, can blur the stem–leaf (axis–appendage) distinction. Compound leaves with apical growth and three-dimensional branching may be seen as developmental mosaics sharing some growth processes with leafy stems (shoots). To cope with fuzzy boundaries between structural categories, fuzzy morphology is proposed as a complementary way of looking at higher plant architecture. Fuzzy morphology treats structural categories (e.g., leaves and stems) as concepts with fuzzy (not sharp) boundaries. The developmental morphology of compound leaves is described comparing Apium repens (Apiaceae) with less typical angiosperms ("misfits") of the rheophyte family Podostemaceae, especially Marathrum rubrum, Mourera fluviatilis, and Tristicha trifaria. In some taxa within the Podostemaceae, typical leaf characteristics may be replaced by new properties, e.g., 90° switch of symmetry plane of the leaf primordium with production of pinnae or lobes along the adaxial and abaxial margin in Marathrum rubrum and Mourera fluviatilis. In Tristicha trifaria, compound photosynthetic appendages (called ramuli) combine developmental characters of typical leaves and typical stems. Thus, they may be called leaf-stem intermediates. Fuzziness of structural categories such as leaf and stem is especially obvious in Podostemaceae, which can be seen as the result of saltational evolution. The structural categories of typical flowering plants are transcended in the Podostemaceae because of developmental changes, resulting in organs with unique combinations of features. Key words: leaf development, developmental mosaic, Apium, Marathrum, Mourera, Tristicha.
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Przyborowski, Łukasz, Anna Łoboda, and Robert Bialik. "Experimental Investigations of Interactions between Sand Wave Movements, Flow Structure, and Individual Aquatic Plants in Natural Rivers: A Case Study of Potamogeton Pectinatus L." Water 10, no. 9 (August 30, 2018): 1166. http://dx.doi.org/10.3390/w10091166.
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Long-duration measurements were performed in two sandy bed rivers, and three-dimensional (3D) flow velocity and bottom elevation changes were measured in a vegetated area and in a clear region of a river. Detailed flow velocity profiles downstream and upstream of a single specimen of Potamogeton pectinatus L. were obtained and the bed morphology was assessed. Potamogeton plants gathered from each river were subjected to tensile and bending tests. The results show that the existence of the plants was influenced by both bottom and flow conditions, as the plants were located where water velocity was lower by 12% to 16% in comparison to clear region. The characteristics of the flow and sand forms depended on the cross-sectional arrangement of the river, e.g., dunes were approximately four times higher in the middle of the river than in vegetated regions near the bank. Furthermore, the studied hydrophytes were too sparse to affect water flow and had no discernible impact on the sand forms’ movements. The turbulent kinetic energy downstream of a single plant was reduced by approximately 25%. Additionally, the plants’ biomechanical characteristics and morphology were found to have adjusted to match the river conditions.
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LIANG, Sheng-Min, Dao-Ju JIANG, Miao-Miao XIE, Ying-Ning ZOU, Qiang-Sheng WU, and Kamil KUČA. "Physiological responses of mycorrhizal symbiosis to drought stress in white clover." Notulae Botanicae Horti Agrobotanici Cluj-Napoca 49, no. 1 (March 24, 2021): 12209. http://dx.doi.org/10.15835/nbha49112209.
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The aim of the present study was to analyze the effects of two arbuscular mycorrhizal fungi (AMF), Funneliformis mosseae and Paraglomus occultum, on leaf water status, root morphology, root sugar accumulation, root abscisic acid (ABA) levels, root malondialdehyde (MDA) content, and root antioxidant enzyme activities in white clover (Trifolium repens L.) exposed to well-watered (WW) and drought stress (DS) conditions. The results showed that root colonization by F. mosseae and P. occultum was significantly decreased by 7-week soil drought treatment. Under drought stress conditions, mycorrhizal fungal treatment considerably stimulated root total length, surface area and volume, as compared with non-mycorrhizal controls. In addition, inoculation with arbuscular mycorrhizal fungi also increased leaf relative water content and accelerated the accumulation of root glucose and fructose under drought stress. Mycorrhizal plants under drought stress registered higher activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) and ABA levels in roots, while lower MDA contents, relative to non-mycorrhizal plants. As a result, mycorrhiza-inoculated plants represented better physiological activities (e.g. antioxidant defense systems, root morphology, and sugar accumulation) than non-inoculated plants in response to soil drought, whilst P. occultum had superior effects than F. mosseae.
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Hossain, MZ, S. Sikder, A. Husna, S. Sultana, S. Akhter, A. Alim, and JC Joardar. "Influence of Water Stress on Morphology, Physiology and Yield Contributing Characteristics of Rice." SAARC Journal of Agriculture 18, no. 1 (July 25, 2020): 61–71. http://dx.doi.org/10.3329/sja.v18i1.48382.
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Water stress or drought is one of the main reasons behind the lower productivity of rice–a widely popular nutritious cereal crop and the staple food for a large portion of the world’s population. A pot experiment was conducted to investigate the effect of water stress on three rice varieties e.g. Banglamoti, Vittiatash and Atash balam in a silty clay soil. To identify whether less water affects rice production, rice plants were cultivated under five different water treatments, T1: flooding at 5 cm depth, T2: flooding at 3 cm depth, T3: saturated water condition, T4: water content@75% saturation, and T5: water content @50% saturation, and were arranged in a completely randomized design with three replications. Morphology, yield and physiological parameters of the rice plants were evaluated. Treatment below saturation did not produce any yield for all the rice varieties studied. All the morphological parameters and yields (e.g. dry weight of plants, plant height, tiller number, panicle number, grain number, grain weight, 1000 seed weight, and harvest index) showed a lower value under water deficient condition. Relative water content and water use efficiency declined with declining water content which represented the variations in their physiological responses to water stress. The grain content per panicle as well as 1000 grain weight of the rice varieties was maximum at saturation condition. Highest harvest index was observed for Vittiatash rice variety at saturated condition. Flooding the soil with either 5 cm or 3 cm depth did not produce any significant change in the studied parameters which indicated that approximately 2 cm water can easily be curtailed which may not affect the production of rice.
SAARC J. Agri., 18(1): 61-71 (2020)
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Knittel, R., and E. J. Pell. "Effects of simulated acidic rain on upper leaf surface of Zea mays foliage." Canadian Journal of Botany 69, no. 12 (December 1, 1991): 2637–42. http://dx.doi.org/10.1139/b91-330.
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Experiments were conducted to determine the histological effects of simulated acidic rain on the cuticle of Zea mays L. cv. B73 × Mo 17 and to ascertain whether subsequent drought stress might elicit interacting effects. Greenhouse-grown plants were treated twice weekly with simulated acidic rain of pH 5.0 or 3.0 for 3–4 weeks. Half of the plants in each pH treatment were then subjected to a 10-day drought stress by withholding water, while the remaining plants continued to receive rain treatments. At the end of the treatment period, leaf tissue was sampled and fixed for light or scanning electron microscopy. Small elongated white lesions approximately 1 mm in diameter appeared in a random pattern on leaves 5–7 that were treated with rain of pH 3.0 for 3 weeks. Plants treated with rain of pH 5.0 did not exhibit these lesions. Lesions were clearly defined areas of collapsed necrotic tissue extending through the leaf. Within lesions, the basal region of 50% of the trichomes had collapsed bases in confluence with adjacent cells. Epicuticular morphology was unaffected by simulated acidic rain or drought stress and appeared as a crystalline platelet-like formation. From our observations, it appeared that factors that maximized droplet retention or droplet deposition, e.g., leaf wettability and leaf orientation, maximized lesion formation. Drought stress had no observable influence on the cuticle of plants treated with either simulated acidic rain treatment. Key words: corn, acid rain, drought stress, histology, cuticle, transpiration.
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Luintel, Sanjeev, Sabina Gyawali, Babu Ram Paudel, Mani Shrestha, and Lokesh Ratna Shakya. "Morphological Variation of Leaf Pattern of the Nepalese Taraxacum Spp. (Asteraceae)." Himalayan Biodiversity 5, no. 1 (December 28, 2017): 9–15. http://dx.doi.org/10.3126/hebids.v5i1.36123.
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Morphological variation of leaf pattern is very common in flowering plants to non-flowering plants that were used to differentiate the species in genus to species level. In this study, we used leaf morphology as the key characters to separate the species of Nepalese Taraxacum. Samples were collected from different parts of Nepal and herbarium specimen were observed to find the variation between the different species of Taraxacum. Our study shows that the presence of two distinct group in this genus Taraxacum. Taxa one is characterized by leaf with double margin (e.g. Taraxacum eriopodum along with 3 other species) and another group is characterized by leaf with single margin (e.g. Taraxacum tibetanum along with 5 other species).
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Sheng, Qianqian, Congzhe Liu, Min Song, Jingyuan Xu, and Zunling Zhu. "Comprehensive Transcriptome Analysis of Rare Carpinus putoensis Plants under NO2 stress." Genes 12, no. 5 (May 17, 2021): 754. http://dx.doi.org/10.3390/genes12050754.
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We evaluated a transcriptome using high-throughput Illumina HiSeq sequencing and related it to the morphology, leaf anatomy, and physiological parameters of Carpinus putoensis putoensis under NO2 stress. The molecular mechanism of the C. putoensis NO2 stress response was evaluated using sequencing data. NO2 stress adversely affected the morphology, leaf anatomy, and total peroxidase (POD) activity. Through RNA-seq analysis, we used NCBI to compare the transcripts with nine databases and obtained their functional annotations. We annotated up to 2255 million clean Illumina paired-end RNA-seq reads, and 250,200 unigene sequences were assembled based on the resulting transcriptome data. More than 89% of the C. putoensis transcripts were functionally annotated. Under NO2 stress, 1119 genes were upregulated and 1240 were downregulated. According to the KEGG pathway and GO analyses, photosynthesis, chloroplasts, plastids, and the stimulus response are related to NO2 stress. Additionally, NO2 stress changed the expression of POD families, and the HPL2, HPL1, and POD genes exhibited high expression. The transcriptome analysis of C. putoensis leaves under NO2 stress supplies a reference for studying the molecular mechanism of C. putoensis resistance to NO2 stress. The given transcriptome data represent a valuable resource for studies on plant genes, which will contribute towards genome annotations during future genome projects.
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Dugle, Janet R., and Janice L. Hawkins. "Leaf development and morphology in ash: influence of gamma radiation." Canadian Journal of Botany 63, no. 8 (August 1, 1985): 1458–68. http://dx.doi.org/10.1139/b85-202.
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Under the stress of long-term exposure to gamma radiation at dose rates ranging from 1.83 to 62.48 mGy/h, planted saplings of black ash (Fraxinus nigra Marsh.) responded in a variety of ways. These were compared with naturally growing black ash trees and saplings and with green ash (F. pennsylvanica Marsh.). With increasing dose, development time shortened, the number of leaflets decreased, and phyllotaxy changed from opposite to helical. The LD50 (lethal dose to 50% of exposed plants) (acute, seed germination) was 98 for F. nigra and 174 Gy for F. pennsylvanica. In black ash, the long-term LR50 (lethal dose rate to 50% of exposed plants, in milligrays per hour) has leveled off at approximately 14 mGy/h, while the accumulative LD50 (total accumulated lethal dose to 50% of exposed plants, in grays) continued to increase with additional irradiation, and after 11 years of irradiation was over 900 Gy. Plantation black ash is surviving, and even thriving, at a dose rate of 15.6 mGy/h, which may be a stable survival dose rate. Leaves in the two species are similar, with more leaflets per leaf on later developed nodes. Leaf size increased with total accumulated dose. Green ash is surviving at the highest dose rate at which it has been found (5.93 mGy/h). The frequency of morphological changes, most of which are teratological (e.g., apparent fused leaves, alternate or missing leaflets, chlorophyll mottling and sectoring, abnormal venation, irregular leaves), increased with radiation dose. In locations with severe winters, stresses during the winter dormant period are very important to survival. It is proposed that some of the features that enable ash to survive in a "harsh" environment may help it to tolerate the stress of gamma irradiation better than other species.
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Silvester, Warwick B., Julie Whitbeck, Janet K. Silvester, and John G. Torrey. "Growth, nodule morphology, and nitrogenase activity of Myrica gale with roots grown at various oxygen levels." Canadian Journal of Botany 66, no. 9 (September 1, 1988): 1762–71. http://dx.doi.org/10.1139/b88-242.
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Myrica gale L. plants were inoculated with Frankia strain HFP M+g15 and grown for 28 days with root systems exposed to 2, 5, 10, 21, and 40 kPa O2. Plant growth was similar under all treatments, except for a small decrease in final size of plants at 2 kPa O2. At the end of the experiment nitrogenase activity of representative plants was analyzed over a variety of Po2 levels using an open-flow cuvette. Optimum nitrogenase activity was found at Po2 levels close to the growth Po2 in all cases and plants showed no short-term adaptation to oxygen. Specific activity of maximum nitrogenase was similar for all treatments, being within a factor of two. Nitrogenase activity showed rapid transient responses to step shifts in Po2 during assay and irreversible decline in activity at Po2 levels above optimum. Morphological responses to changing Po2 include a dramatic increase in nodule-root growth, inversely proportional to ambient Po2, and a variety of internal structural changes reducing nodule ventilation with Po2 increase. No modification in vesicle envelope thickness was observed over the range of Po2 studied. We conclude that oxygen protection in M. gale nodules operates through a complex suite of morphological controls, but that modification of nodule-root surface area is probably the prime mechanism.
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Hernández, José Carlos, Sabrina Clemente, Eliseba García, and Justin S. McAlister. "Planktonic stages of the ecologically important sea urchin, Diadema africanum: larval performance under near future ocean conditions." Journal of Plankton Research 42, no. 3 (April 21, 2020): 286–304. http://dx.doi.org/10.1093/plankt/fbaa016.
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Abstract Diadema africanum is a recently described sea urchin from the Eastern Atlantic archipelagos, and adults play a major ecological role mediating the transition between two alternative ecosystem states: macroalgal beds and urchin barrens. The aim of this study was to describe for the first time the egg characteristics, fertilization and larval development. To determine basic life-history characteristics for this species, we reared larvae through to metamorphic competence under an energy shortage experiment and temperature–pH experiments to characterize the morphological plasticity of larval responses to actual and future oceanic conditions. D. africanum produces eggs that are larger both in diameter (82.7 μm) and volume (0.30 nl) than the eggs of both Diadema antillarum (70.0 μm, 0.18 nl) and Diadema mexicanum (68.0 μm, 0.16 nl). Larval development is similar to other species within the Family Diadematidae, with a Echinopluteus transversus larval type morphology. The combined effects of the climate change-related environmental factors resulted in a reduction in fitness of D. africanum at the warmer limit of its thermal range when combined with low pH. Results suggest that the egg and larval life-history characteristics of D. africanum may have evolved to facilitate long-distance oceanic transport; however, near-future oceanic conditions may compromise larval survival.
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Nik Yusuf, Nik Alnur Auli, Ernie Surianiy Rosly, Mazlan Mohamed, Bashree Abu Bakar, Mahani Yusoff, Muhammd Azwadi Sulaiman, and Muhammad Iqbal Ahmad. "Waste Banana Peel and its Potentialization in Agricultural Applications: Morphology Overview." Materials Science Forum 840 (January 2016): 394–98. http://dx.doi.org/10.4028/www.scientific.net/msf.840.394.
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The reserach is focused on the resistance of bio-polymer thin film to bio-degradation in compost soil from renewable resources based on waste banana peel and waste egg shell in polymer matrix. The combination of waste banana peel and waste egg shell in producing of bio-mulching film is a new inovation in agricultural industry . Bio-mulching film is a biodegradable plastics films that can help in increasing the moisture content of soil and improving the soil ingredients in order to make the plants grow well. The thin film is produced by using the waste banana banana peelas the reinforcement fiber, eggshell as filler and epoxy resin as matrix. The thickness of thin film was in between 0.10 mm to 0.15 mm. The epoxy/waste banana banana peelwith eggshell (EWE) 10%, were affected by bio-degradation in soi burial test where the occurances of surface damages, which in turn enhances the degradation of physical properties.
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Mah, Jasmine Jenji, David Llewellyn, and Youbin Zheng. "Blackout Reduces Height of Easter Lily but End-of-day Red Light Treatment Using Light-emitting Diodes Does Not." HortTechnology 30, no. 2 (April 2020): 156–62. http://dx.doi.org/10.21273/horttech04496-19.
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One principle for reducing undesirable stem extension in greenhouse production is to counteract the decrease in red-to-far red ratio that occurs naturally during twilight periods. This study evaluated three lighting treatments on the morphology of easter lily (Lilium longiflorum): 1) a 1-hour end-of-day treatment providing 20 μmol·m−2·s−1 of monochromatic red light (EOD R), 2) blackout curtains closed 45 to 75 minutes before sunset and kept closed until 0 to 60 minutes after sunrise (BO), and 3) a control with natural twilight (CTRL). Plants under the BO treatment were 11% shorter than CTRL, while plants exposed to EOD R did not differ in height compared with BO or CTRL. There were no treatment effects on any other measured parameters, including aspects of flowering.
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Popović, Branka, Snežana Tanasković, and Sonja Gvozdenac. "Effects of the Low-Level Western Corn Rootworm Egg Infestation on Maize Plants in the Field." Contemporary Agriculture 68, no. 1-2 (June 1, 2019): 28–33. http://dx.doi.org/10.2478/contagri-2019-0006.
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Summary From the economic perspective, the western corn rootworm (WCR), Diabrotica virgifera sp. virgifera (Col., Chrysomelidae), poses the gravest threat to the field maize production in Serbia. The purpose of this study is to examine the impact of WCR larvae on the morphology of maize characters during a low-level artificial egg infestation. A field experiment involving the Serbian cultivar ‘NS-640’ was carried out in Bečej, Vojvodina Serbia, in 2016. In the experimental field, a total of 96 maize plants were selected, marked and arranged in 48 pairs. Each pair consisted of an infested plant (WCR eggs injected in the root zone) and an uninfested plant (distillate water injected in the root zone). The number of leaves, height and stem diameter of the plants observed were recorded. Root damage and root weight were measured and evaluated at the end of the trail. For the purpose of statistical analysis, the non-parametric Kruskal-Wallis one-way analysis of variance and a correlation matrix were used. The statistical analysis performed indicate a highly significant difference in the number of leaves and plant height between the infested and uninfested maize plants examined in July (the third field observation). During the last field inspection, significant differences were recorded only between the stem diameters of the infested and uninfested maize plants. A negative correlation was found to exist between the root damage and root weight of the plant pairs. There were positive correlations between the stem diameter, plant height and number of leaves of the infested plants, whereas positive correlations were found between the root damage and plant height of the uninfested plants.
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PONTI, Donatella, M. LUISA MANGONI, Giuseppina MIGNOGNA, Maurizio SIMMACO, and Donatella BARRA. "An amphibian antimicrobial peptide variant expressed in Nicotiana tabacum confers resistance to phytopathogens1." Biochemical Journal 370, no. 1 (February 15, 2003): 121–27. http://dx.doi.org/10.1042/bj20021444.
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Esculentin-1 is a 46-residue antimicrobial peptide present in skin secretions of Rana esculenta. It is effective against a wide variety of micro-organisms, including plant pathogens with negligible effects on eukaryotic cells. As a possible approach to enhance plant resistance, a DNA coding for esculentin-1, with the substitution Met-28Leu, was fused at the C-terminal end of the leader sequence of endopolygalacturonase-inhibiting protein, under the control of the cauliflower mosaic virus 35S promoter region, and introduced into Nicotiana tabacum. The antimicrobial peptide was isolated from the intercellular fluids of healthy leaves of transgenic plants, suggesting that it was properly processed, secreted outside cells and accumulated in the intercellular spaces. The morphology of transgenic plants was unaffected. Challenging these plants with bacterial or fungal phytopathogens demonstrated enhanced resistance up to the second generation. Moreover, transgenic plants displayed insecticidal properties.
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Skórzyńska, Ewa, Józef Bednara, and Tadeusz Baszyński. "Some aspects of runner bean plant response to cadmium at different stages of the primary leaf growth." Acta Societatis Botanicorum Poloniae 64, no. 2 (2014): 165–70. http://dx.doi.org/10.5586/asbp.1995.023.
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Changes in morphology of primary leaves and ultrastructure of chloroplasts have been studied in runner bean plants (<i>Phaseolus coccineus</i> L., cv. Piękny Jaś) grown on Knop nutrient solution either without Cd or supplied with 2.5-10<sup>-5</sup> M Cd (in the form of 3CdSO<sub>4</sub>•8H<sub>2</sub>O) in different stages of growth. The metal applied to the nutrient solution during the early stages of growth resulted in a reduction of the leaf area, chlorophyll accumulation increase and small decrease in PSII activity. Conversely to it Cd added at the end of primary leaf growth revealed almost unchanged leaf area but a significant decrease of chlorophyll level and PSII activity. Changes in the leaf morphology (large intercellular spaces in pallisade as well as spongy mesophyll) and ultrastructure of chloroplasts (degradation of intergranal thylakoids and appearance of numerous plastoglobuli) indicating their disorganization were observed only in plants treated with Cd at the end of primary leaf growth. Morphological and ultrastructural disturbances related to the growth stages are discussed in relation to functional changes of the photosynthetic apparatus.
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Gramig, Greta G., and David E. Stoltenberg. "Adaptive Responses of Field-Grown Common Lambsquarters (Chenopodium album) to Variable Light Quality and Quantity Environments." Weed Science 57, no. 3 (June 2009): 271–80. http://dx.doi.org/10.1614/ws-08-120.1.
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Field experiments were conducted to determine whether exposure to reduced red : far-red light ratios (R : FR) typical of crop–weed environments was associated with adaptive changes in morphology, productivity, and fecundity of common lambsquarters. Plants were grown in reduced or ambient R : FR environments (both in full sunlight) until initiation of flowering, after which plants were grown in full sunlight or partial shade. At initiation of flowering, plants that had been exposed to reduced R : FR exhibited greater specific leaf area, stem elongation, main stem leaf area, specific stem length, and main stem mass compared with plants exposed to ambient R : FR. However, biomass allocation to stems, leaves, and roots did not differ between vegetative-stage R : FR treatments. At the end of flowering, morphology and productivity of plants exposed to partial shade did not differ between vegetative-stage R : FR treatments. In contrast, plants exposed to full sunlight during flowering after exposure to reduced R : FR during the vegetative stage had less total plant mass, less total leaf area, greater stem elongation, greater specific stem length, and a greater ratio of main stem to total stem mass compared with plants exposed to ambient R : FR during the vegetative stage. At physiological maturity, plants exposed to reduced R : FR during the vegetative stage and to partial shade during the reproductive stage had less total seed mass and fewer seeds compared with plants exposed to ambient R : FR during the vegetative stage and to partial shade during the reproductive stage. Fecundity of plants exposed to full sunlight during the reproductive stage did not differ between vegetative-stage R : FR treatments. These results indicate that exposure of common lambsquarters to reduced R : FR during the vegetative stage was maladaptive at later stages of growth in competitive environments, and suggest that interactions of light quality and quantity are important determinants of common lambsquarters fecundity.
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Simon, J. C., M. L. Decau, J. C. Avice, A. Jacquet, F. Meuriot, and J. M. Allirand. "Effects of initial N reserve status and residual leaf area after cutting on leaf area and organ establishment during regrowth of alfalfa." Canadian Journal of Plant Science 84, no. 4 (October 1, 2004): 1059–66. http://dx.doi.org/10.4141/p03-118.
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Nitrogen reserves in remaining organs and residual leaf area after cutting have long been recognized as key factors during alfalfa (Medicago sativa L.) regrowth. The present work examined which morphological components were influenced by contrasting initial N status and residual leaf area during 29 d of regrowth after cutting at 15 cm height. Two levels of initial N reserves (high and low) and of residual leaf areas (not or completely defoliated) were combined in four treatments. Both factors affected shoot dry matter (DM) production at the end of regrowth. The increase in DM of new organs observed with high N reserves resulted from a combination of short- and long-term effects on plant morphology; i.e., (1) an increase in the rate of axis appearance from the crown in the early regrowth stage (day 0–9) and (2) an increase in individual leaf area (ILA) all along the regrowth. Compared with completely defoliated plants, plants with a residual leaf area at cutting exhibited an increased rate of axillary stems appearance all along the regrowth. Then the architecture of plants with a residual leaf area was more branched than the one of defoliated plants. This increase in branching was always associated with smaller ILA. Hence, differences in plant leaf area were only significant in the early growth stage. This suggested that differences observed in new stems DM at the end of the regrowth were established by day 9 and remained unchanged in late regrowth. Our results clearly showed that initial N reserve status and residual leaf area both significantly modify the dynamic of leaf area establishment and new organ growth of alfalfa. Key words: Medicago sativa L., defoliation, morphology, N storage, stems regrowth
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Mann, David G., and Aloisie Poulíčková. "Homothallism, morphology and phylogenetic position of a new species of Sellaphora (Bacillariophyta), S. pausariae." Plant Ecology and Evolution 152, no. 2 (July 9, 2019): 203–18. http://dx.doi.org/10.5091/plecevo.2019.1626.
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Background and aims – The eutrophic Blackford Pond in Edinburgh has already provided the holotypes of six other Sellaphora species. A further undescribed species is present and requires description and characterization.
Methods – Clones of the new species are characterized by light (LM) and scanning electron microscopy (SEM) and molecular phylogenetics (from a concatenated five-gene alignment of 18S rDNA, 28S rDNA, 23S rDNA, cox1 and rbcL, and a two-gene alignment of cox1 and rbcL).
Key results – Sellaphora pausariae sp. nov. is named in honour of Dr Eileen Cox (‘pausaria’ = a lady coxswain). In molecular phylogenies, small-celled Sellaphora species (‘minima’ and ‘seminulum’ morphologies) branch off at the base of Sellaphora, though nodes are not well supported. Species and demes previously classified in either “Navicula pupula” or “Navicula bacillum” group into three very well supported clades (numbered 1–3). Although appearing in LM and SEM like a smaller, more delicate version of S. obesa, S. pausariae (clade 1) is not closely related to S. obesa (clade 2). Features of Sellaphora pausariae not confirmed previously in any Sellaphora but possibly widespread are: (a) hymenes with pores arranged in a regular scatter; (b) a stepped mantle near the poles; and (c) a ‘primodominant’ girdle comprising a wide band 1, a segmental band 2, and two extremely thin bands at the abvalvar end of the girdle. Sellaphora pausariae is homothallic; a deficiency of interclonal pairings in two-clone mixtures is interpreted as reflecting the tendency of cells to mate with their immediate neighbours.
Conclusions – Morphologically, the new species can be differentiated from existing described species, though only problematically from some informally named demes. Molecularly, it is clearly characterized by the five genes sequenced. Girdle terminology needs expansion (e.g. to distinguish primodominant girdles from ‘graded’ ones, in which the bands gradually decrease in width and structural complexity from the valve outwards).
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Kessler, André, and Alexander Chautá. "The ecological consequences of herbivore-induced plant responses on plant–pollinator interactions." Emerging Topics in Life Sciences 4, no. 1 (June 15, 2020): 33–43. http://dx.doi.org/10.1042/etls20190121.
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Plant induced responses to herbivory have long been found to function as plant direct and indirect defenses and to be major drivers of herbivore community and population dynamics. While induced defenses are generally understood as cost-saving strategies that allow plants to allocate valuable resources into defense expression, it recently became clear that, in particular, induced metabolic changes can come with significant ecological costs. In particular, interactions with mutualist pollinators can be significantly compromised by herbivore-induced changes in floral morphology and metabolism. We review recent findings on the evidence for ecological conflict between defending against herbivores and attracting pollinators while using similar modes of information transfer (e.g. visual, olfactory, tactile). Specifically, we discuss plant traits and mechanisms through which plants mediate interactions between antagonists and mutualist and present functional hypotheses for how plants can overcome the resulting conflicts.
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Rudall, P. "Development of the ovule and megagametophyte in Ecdeiocolea monostachya." Australian Systematic Botany 3, no. 2 (1990): 265. http://dx.doi.org/10.1071/sb9900265.
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Ovule and megagametophyte development is described for the first time in Ecdeiocoleaceae, a small Western Australian family that has affinities with Restionaceae. The mature embryo sac has an egg apparatus, but other nuclei usually degenerate. The nucellus proliferates at the chalazal end of the embryo sac to forma prominent cup-shaped region that has no obvious homologue among related families in Poales, or tother monocotyledons. The data confirm evidence from anatomy and pollen morphology that Ecdeiocolea does not belong in Restionaceae, but do not indicate obvious relationships with other families.
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Gruber, Margaret, Birgitte Skadhauge, Min Yu, Alister Muir, and Kenneth Richards. "Variation in morphology, plant habit, proanthocyanidins, and flavonoids within a Lottus germplasm collection." Canadian Journal of Plant Science 88, no. 1 (January 1, 2008): 121–32. http://dx.doi.org/10.4141/p06-158.
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Lotus species collec ted from a range of geographical locations were evaluated for relationships between plant habit and size, leaf proanthocyanidin (PA) content, flower colour, stem colour, leaf colour, trichome density, and geographic origin. No relationships occurred between leaf PA concentration and morphological trait or collection site. Trichome coverage was moderately correlated with plant size (r = -0.70). Several accessions, e.g., L. angustissimus L. and L. castellanis Boiss. & Reut., consisted of small, trichome-covered plants distinct from the large, glabrous plants typical of the model species L. corniculatus var. japonicus ecotype Gifu B129. These two morphology types were also represented among the tan mutants of Gifu B129. Due to the importance of trichomes and PA in plant defence, PA composition was compared between L. angustissimusand tan1 (both representing the small trichome-covered phenotype) and ecotype Gifu B129 and tan2 (both representing the large, glabrous phenotype). Both the tan1 and tan2 mutants accumulated substantial amounts of leaf PA similar in size to the small oligomers recovered from leaves of L. angustissimus. PA polymers were undetectable in Gifu B129 leaves, while floral PA extracts of this ecotype included a much larger PA polymer. Flavonoid composition in leaves of tan1 and L. angustissimus was complex, and differed from the simple profile in Gifu B129 leaves. Key words: Lotus, proanthocyanidin, flavonoids, trichomes, morphology, plant habit, variability
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Nishida, Sachiko, Akiyo Naiki, and Takayoshi Nishida. "Morphological variation in leaf domatia enables coexistence of antagonistic mites in Cinnamomum camphora." Canadian Journal of Botany 83, no. 1 (January 1, 2005): 93–101. http://dx.doi.org/10.1139/b04-152.
Full textAbstract:
We examined variation in Cinnamomum camphora (L.) J. Presl (Lauraceae) leaf domatium morphology with respect to domatium inhabitants in the tree's natural habitats. Canonical discriminant analysis revealed that domatium morphology could be classified into four different types: pouch type, domatia with a narrow (about 0.06 mm) pubescent opening; pubescent pit type, domatia with a wider (about 0.21 mm) pubescent opening; glabrous pit type, domatia similar to the pubescent pit type but with a glabrous opening; and dish type, domatia with a wide (about 0.26 mm) glabrous opening. These four domatium types were found in different positions on a leaf, and domatia with narrower openings tended to occur in or near the position between the midrib and basal secondary veins. The four domatium types were associated, respectively, with herbivorous Eriophyidae mites and herbivorous or fungivorous Tarsonemidae mites; with carnivorous Stigmaeidae mites; with Stigmaeidae mites and egg shells or excuviae of carnivorous Phytoseiidae mites; and with egg shells or excuviae of Phytoseiidae mites. These results suggest that different mites use different domatia, even on the same C. camphora leaf. This conclusion may explain the different results in previous reports about domatium fauna. It suggests that ecological interactions within the plantherbivorecarnivore system are complicated.Key words: carnivorous mite, Cinnamomum camphora, domatia, herbivorous mite, inhabitant, morphology.
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Leinonen, Reima, Nadesda Kutenkova, Matti Ahola, Juhani Itämies, and Veli Vikberg. "The ecology, genitalia and larval morphology of Polythrena coloraria Herrich-Schäffer, 1855 (Lepidoptera: Geometridae), with records of its egg parasitoid Telenomus acarnas Kozlov & Kononova, 1977 (Hymenoptera: Scelionidae)." Entomologica Fennica 17, no. 1 (January 1, 2006): 56–64. http://dx.doi.org/10.33338/ef.84288.
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Investigations were made upon the biology and habitat demands of the larvae and adults of Polythrena coloraria in the Kivach nature reserve in the Republic of Karelia, Russia, close to the eastern border of Finland. In the laboratory females laid eggs only on Ribes nigrum, although other plants were also available. Eggs were found in the field under the leaves of this plant, too. Instead larvae were not found in the field. In the laboratory they did not eat any other plants offered. In addition, the male and female genitalia and larval morphology are described. Based on these characteristics, the systematic position of the species is discussed. A parasitoid wasp Telenomus acarnas (Hymenoptera, Scelionidae, Telenominae) is reported fromthe eggs of P. coloraria. It seems to be the first host record for this parasitoid wasp.
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Chen, Chin-Mu, Tzu-Yao Wei, and Der-Ming Yeh. "Morphology and Inheritance of Double Floweredness in Catharanthus roseus." HortScience 47, no. 12 (December 2012): 1679–81. http://dx.doi.org/10.21273/hortsci.47.12.1679.
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A double-flowered periwinkle [Catharanthus roseus (L.) G. Don.] mutant TYV1 was identified and the morphology and inheritance of the double-flowered phenotype was studied. TYV1 has an outer salverform whorl of petals and an additional inner funnel-shaped whorl of petals originating from the apex of the corolla. The apex of corolla tube forms a narrow opening. There are hairs under the opening at the apex. The stigma in this mutant is set below the anthers. The overlap between the top end of the pistil and bottom ends of anthers in TYV1 flowers at 1 to 2 days after anthesis is 0.56 ± 0.01 mm. TYV1 could be used as either the male or female parent in crossing. Self-pollinated TYV1 produced all double-flowered progeny compared with self-pollinated single-flowered cultivars Little Pinkie and Titan Burgundy, which produced all single-flowered progeny. F1 plants between TYV1 and ‘Little Pinkie’ or ‘Titan Burgundy’ were all single. Three F2 populations segregated into 3 single: 1 double ratio. Backcrossing F1 to seed parents also indicated that a double-flowered form was controlled by a recessive allele. A single dominant gene expressed in the homozygous or heterozygous state resulted in the single-flowered phenotype. All the young seedlings of self-pollinated TYV1 and double-flowered progeny had distorted leaves before the sixth pair of leaves emerged.
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Otten, Léon, and Anne Helfer. "Biological Activity of the rolB-like 5′ End of the A4-orf8 Gene from the Agrobacterium rhizogenes TL-DNA." Molecular Plant-Microbe Interactions® 14, no. 3 (March 2001): 405–11. http://dx.doi.org/10.1094/mpmi.2001.14.3.405.
Full textAbstract:
The iaaM gene from different plant-associated bacteria encodes a tryptophan monooxygenase (IaaM) that catalyzes the synthesis of indole-3-acetamide (IAM), a precursor of indole-3-acetic acid (IAA). Unlike the IaaM proteins from other bacteria, Agrobacterium spp. T-DNA-encoded IaaM proteins carry a 200 amino acid N-terminal extension with low homology to various members of the RolB protein family. This family is composed of 18 highly divergent T-DNA-encoded proteins, the basic functions of which are still largely undetermined. Deletion of the 5′rolB-like extension of the iaaM gene from Agrobacterium tumefaciens strain Ach5 did not lead to a reduction in IAM synthesis in plants. When expressed in tobacco, the rolB-like fragment did not affect growth or morphology. An iaaM homolog (A4-orf8) from the TL-DNA of Agrobacterium rhizogenes strain A4 also was investigated. Neither the full-size A4-orf8 gene nor the 5′-truncated form induced detectable IAM synthesis. Plants expressing the rolB-like part of the A4-orf8 gene, however, were dwarfed and mottled to various extents and synthesized abnormally high amounts of glucose, fructose, sucrose, and starch.
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Pranoto, Hadi, Akhmad Askan, and Bambang Supriyanto. "Identifikasi Karakter Morfologi Dan Agronomi Tanaman Padi F1 Hasil Silang Balik Resiprok Kambang/Pandan Ungu//Pandan Ungu." Jurnal Agroekoteknologi Tropika Lembab 2, no. 1 (August 1, 2019): 15. http://dx.doi.org/10.35941/jatl.2.1.2019.2521.15-19.
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This research was conducted to obtain hybridization which has superior character and to know the agronomic and morphological characters of F1 generation from reciprocal crossof Kambang/Pandan Ungu//Pandan Ungu, this research uses a reciprocal cross method (cross between F1 from a single cross with male elders) to produce F1 plants that will change the morphological and agronomic character. This research was conducted at the screen house area in the Faculty of Agriculture, Mulawarman University, Until the of January 2018 to September 2018. The results of this identification showed that from 161 spikelet castrated obtained as many as 60 grains with a percentage of fertility 37.27%, and then sowing as many as 30 seeds (50%), plants that successfully grew and could be used there were 21 plants (70%) character morphology and agronomic on F1 plants more dominant in the character of Pandan Ungu rice. The dominan characters are leaf color, ligula color, uricle color, midrib color, leaf surface, stigma color, grain end color, lemma and palea color, number of wildings, breed ability, number of productive wildingss, panicle type, yellowing of leaves, diameter of root stock, and harvesting the crop.
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Gnanamurthy, S., and D. Dhanavel. "Effect of EMS on Induced Morphological Mutants and Chromosomal Variation in Cowpea (Vigna unguiculata (L.) Walp)." International Letters of Natural Sciences 22 (August 2014): 33–43. http://dx.doi.org/10.18052/www.scipress.com/ilns.22.33.
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Effect of EMS (ethyl methane sulphonate) on induced morphological mutants and chromosomal variation in cowpea was studied using five different doses of mutagen along with a control in randomized blocked design with three replications. The morphological mutants there are two types of viable and chlorophyll mutants. Viable mutant contains tall, dwarf, early maturity, late maturity, leaf mutants pod mutant and flower mutants. The frequency of chlorophyll mutant contains albino, xantha and viridis. This concentration can damage or modify important components of plant cells and have been reported to affect the morphology, anatomy, biochemistry and physiology of plants differentially depending on the concentration level. These effects include changes in the cellular structure and metabolism of the plants e.g., dilation of thylakoid membranes, alteration in photosynthesis, modulation of the antioxidative system and accumulation of phenolic compounds. The morphological and chromosomal variation was found to be mutagen sensitive in somatic cells of cowpea. It was found to increase with increasing the concentration of EMS in Cowpea plants. The chemical mutagen like ethyl methane sulphonate induces high frequency of chromosomal changes like anaphasic bridge; anaphasic laggard, anaphasic bridge and clumbing of chromosome were including control plants also observed.
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Gröcke, Darren R. "Distribution of C3 and C4 Plants in the Late Pleistocene of South Australia Recorded by Isotope Biogeochemistry of Collagen in Megafauna." Australian Journal of Botany 45, no. 3 (1997): 607. http://dx.doi.org/10.1071/bt96040.
Full textAbstract:
Stable carbon-isotope analyses (expressed as a 13C:12C ratio relative to that of a standard: δ13C) on fossilised collagenic material in megafaunal bones can provide information regarding the palaeodiet (e.g. C3 and/or C4 plants) of these animals. Isotope analyses were performed on collagenic material extracted from bones of Sthenurus spp., Diprotodon spp. and Macropus spp. from Cooper Creek, Henschke Cave, Baldina Creek, Dempsey’s Lake and Rocky River in South Australia. The percentage of trees and shrubs estimated from palaeofloral records in south-eastern Australia and the dietary preferences of megafauna were found to be positively correlated. The dietary preferences of megafauna analysed from South Australian localities indicate that megafauna were opportunistic and changed their diet in response to environmental change. This suggests that megafauna diet can not be founded on dental morphology alone. Fossilised collagenic material in vertebrate remains can provide an insight into the broadscale nature of the vegetation. This approach is a good compliment for other palaeoecological data (e.g. sedimentology, spore–pollen, diatoms) by providing evidence for past climates in relation to the proportion of C3 and C4 plants.
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Blanco, Carlos A., Armando Rosario-Lebron, Cheryle A. O’Donnell, Maribel Portilla, Connor Gullbronson, Joseph Mowery, Allan H. Smith-Pardo, et al. "Improving Risk Assessment of Noctuid Pests at North American Ports and Farms by Differentiating Egg Morphology." Annals of the Entomological Society of America 112, no. 5 (June 26, 2019): 443–50. http://dx.doi.org/10.1093/aesa/saz029.
Full textAbstract:
Abstract Heliothine eggs are commonly found on agricultural commodities and ornamental plants transported through domestic and international commerce. Tobacco budworm [Chloridea (Heliothis) virescens (F.)], Chloridea subflexa (Guenée), and the corn earworm [Helicoverpa zea (Boddie)] are indigenous pests of the American continent. Interceptions of the Old World bollworm [Helicoverpa armigera (Hübner)] at various ports of entry into the United States have been detected due to the invasion of this pest in South America, adding to the complexity and importance of decision making at plant inspection stations. The ability to distinguish the eggs of C. virescens from C. subflexa and Helicoverpa species is a critical component for conducting risk assessments by quarantine authorities, taxonomists, and crop consultants. We developed a simple, rapid (~60 min), inexpensive ($0.06 per sample), and accurate (100% reliability) technique to distinguish C. virescens eggs from the possibility of being H. armigera based on the presence, number, and/or size of aeropyle holes on the primary ribs of eggs, near the micropylar rosette. In this location, aeropyles were easily visible at 40× magnification in 213 fresh and ethanol-preserved C. virescens eggs once treated with Hoyer’s solution. A small number of C. subflexa had one or two aeropyles on a few of the primary ribs, whereas no aeropyles were found on 411 H. zea and 269 H. armigera eggs analyzed using optical, electron, and confocal microscopy. We conclude that in most cases multiple aeropyle holes positively identify H. virescens eggs from H. zea or H. armigera, and C. subflexa. This technique potentially will reduce the number of specimens that need to be sent for molecular identification thereby saving program time and resources.
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Diniz, Fábio Oliveira, Sebastião Medeiros Filho, Antônio Marcos Esmeraldo Bezerra, and Francisco José Carvalho Moreira. "Biometria e morfologia da semente e plântula de oiticica." Revista Verde de Agroecologia e Desenvolvimento Sustentável 10, no. 2 (October 14, 2015): 183. http://dx.doi.org/10.18378/rvads.v10i2.2965.
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A carência de trabalhos sobre plantas nativas da Caatinga nordestina é perceptível, sobretudo, no que se refere aos estudos de suas sementes. Dentre as referidas espécies, destaca-se por seus múltiplos usos, a oiticica (Licania rigida Benth). Objetivou-se com este trabalho determinar e descrever a biometria e morfologia da semente e plântula de oiticica. O trabalho foi conduzido no Laboratório de Análises de Sementes do Departamento de Fitotecnia/UFC. Foram realizadas, nas sementes, medições individuais de comprimento, largura e espessura e a determinação morfológica de suas partes internas e externas, além da caracterização da plântula com suas respectivas estruturas. A semente de oiticica é eurispérmica, apresenta comprimento de 3,1 a 5,0 cm, largura de 1,3 a 1,7 cm e espessura de 1,2 a 1,7 cm. O embrião é grande de formato linear, com cotilédones carnosos de cor branca amarelada, dobrados e apresentam nervuras e o eixo hipocótilo-radícula curto. Germinação inicia-se aos 15 dias, sendo hipógea criptocotiledonar. A plântula possui nas faces dos primórdios foliares, uma camada esbranquiçada com aspecto cotonoso.Biometry and morphology of seed and seedling of oiticicaAbstract: Lack of works in native plants of caatinga northeastern is obvious, especially, relating to study of seeds. Among these species, stands out for its multiple uses, the oiticica (Licania rigida Benth). The objective of present experiment was to determinate the biometry and morphology the seed and seedling of Licania rigida. The essay was conducted at the Laboratory of Analysis of Seeds of the Phytotechny Department/UFC. Used were what measurement referent this length, width end thickness as well as detailed description internal end external of seed. Results showed that the seeds are euryspermycs, has length 3.1 to 5.0 cm, width 1.3 to 1.7 cm and thickness 1.2 to 1.7 cm. The embryo is large linear format, with fleshy cotyledons yellowed, folded white and have short ribs and the hypocotyl-radicle axis. Germination starts after 15 days, hypogeal cryptocotylar. The seedling has the faces of the leaf primordia, a whitish layer cotonoso aspect.
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Bujang, Japar Sidik, Norhapizah Ahmad Nazri, Muta Harah Zakaria, Azis Arshad, and Hisao Ogawa. "MORPHOLOGIAL PLASTICITY OF HALODULE SPECIES IN RESPONSE TO DIFFERENT ENVIRONMENTS." Marine Research in Indonesia 33, no. 1 (June 30, 2008): 11–16. http://dx.doi.org/10.14203/mri.v33i1.457.
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Halodule species is widely distributed along the south and east coasts of Peninsular Malaysia, Sabah and Sarawak. Five locations were selected for the study based on different habitat characteristics; sub-tidal shoal (Merambong-2 sites; Tg. Adang Laut-2 sites), coastal lagoon (Merchang-2 sites), inter-tidal beach front (Lawas-l site) and reef atoll lagoon (Pulau Layang-Layang-l site). Samplings and collections of Halodule plants were conducted from August 2002 until May 2004. The result of the study found that Halodule species are found at depth.of -1.5 to-2.7 m in various habitats with substrates from sandy, coralline sand, calcareous sandy-mud, sandy-mud to muddy substrates and can survive in a wide range of salinity, 18-34 psu. They adapt in th,e different environmental conditions through changes in morphology. Water depth (associated with ambient light), sediment type and sediment depth have an influence on the morphology of vegetative components e.g. leaf length, leaf width, erect stem length and rhizome growth pattern. Leaf tip morphology was not affected by habitat types and the environmental characteristics. Leaf tips for H. uninervis are similar in morphology between young and mature leaves. Leaf tips for H. pinifolia varied with an obvious differences between young and mature leaf tips.
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Bruhl, JJ. "Comparative Development of Some Taxonomically Critical Floral Inflorescence Features in Cyperaceae." Australian Journal of Botany 39, no. 2 (1991): 119. http://dx.doi.org/10.1071/bt9910119.
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Morphology at different developmental stages was investigated by dissection and by scanning electron microscopy (SEM) in five sedges: Eleocharis (three species) and Schoenoplectus (both Cyperoideae, Scirpeae), and Lepidosperma (Caricoideae, Schoeneae). In each case all the perianth segments (scales or bristles) were positioned outside the staminal primordia or stamens, consistent with classical interpretations of flowers. Putative exceptions and previous alternative interpretations of floral morphology in the Cyperaceae are discussed. SEM developmental studies of Hypolytreae (e.g. Scirpodendron) are needed for further clarification of interpretative floral/inflorescence morphology in the family.
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Brüchert, Franka, Olga Speck, and Hanns–Christof Spatz. "Oscillations of plants' stems and their damping: theory and experimentation." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 358, no. 1437 (August 13, 2003): 1487–92. http://dx.doi.org/10.1098/rstb.2003.1348.
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Free oscillations of upright plants' stems, or in technical terms slender tapered rods with one end free, can be modelled by considering the equilibrium between bending moments and moments resulting from inertia. For stems with apical loads and negligible mass of the stem and for stems with finite mass but without top loading, analytical solutions of the differential equations with appropriate boundary conditions are available for a finite number of cases. For other cases approximations leading to an upper and a lower estimate of the frequency of oscillation ω can be derived. For the limiting case of ω = 0, the differential equations are identical with Greenhill's equations for the stability against Euler buckling of slender poles. To illustrate, the oscillation frequencies of 25 spruce trees ( Picea sitchensis (Bong.) Carr.) were compared with those calculated on the basis of their morphology, their density and their static elasticity modulus. For Arundo donax L. and Cyperus alternifolius L. the observed oscillation frequency was used in turn to calculate the dynamic elasticity modulus, which was compared with that determined in three–point bending. Oscillation damping was observed for A. donax and C. alternifolius for plants' stems with and without leaves or inflorescence. In C. alternifolius the difference can be attributed to the aerodynamic resistance of the leaves, whereas in A. donax structural damping in addition plays a major role.
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Elrabaya, Daker Taha Dib. "Can the New Waste Morphology Method Predict Sorting Plants Operational and Financial Challenges? A Case Study in Sharjah." Environmental Research, Engineering and Management 77, no. 2 (July 2, 2021): 19–36. http://dx.doi.org/10.5755/j01.erem.77.2.28572.
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This article presents a new approach to analysing municipal waste (MSW) composition, which makes it possible to envisage sorting process efficiency and predict valuable secondary raw material (SRM) losses during sorting. The study also enables to foresee financial losses related to the quality recyclables that are reclaimed from MSW. In this article, samples from MSW delivered to Bee’ah site in Sharjah in the United Arab Emirates (UAE) were analysed to define their composition. The novelty in this research was the mechanical and physical property analysis for the MSW components and the prediction mechanism used to foresee the possible recovery rate of a potential mechanical sorting process. The results were compared with those that would be obtained from traditional composition analysis to end up with shocking results. It was concluded that any mechanical sorting process, designed based on traditional analysis data, is mostly to face tremendous operational and financial challenges in the UAE. This is due to the input material shape, size, moisture content and other factors that change the way SRM components respond to sorting mechanisms. The study was able not only to explain the challenges faced by all the UAE sorting facilities, but also to show how to prevent such unsatisfactory performance in the future. The study concluded the reasons behind the MSW component deterioration and provided additional recommendations to extract more benefits from the new waste morphology approach.
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Masselter, Tom, Sandra Eckert, and Thomas Speck. "Functional morphology, biomechanics and biomimetic potential of stem–branch connections in Dracaena reflexa and Freycinetia insignis." Beilstein Journal of Nanotechnology 2 (March 24, 2011): 173–85. http://dx.doi.org/10.3762/bjnano.2.21.
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Branching in plants is one of the most important assets for developing large arborescent growth forms with complex crowns. While the form and development of branching in gymnosperms and dicotyledonous trees is widely understood, very little is known about branching patterns and the structure of branch–stem-junctions in arborescent monocotyledons. For a better and quantitative understanding of the functional morphology of branch–stem-junctions in arborescent monocotyledons, we investigated the two species Dracaena reflexa and Freycinetia insignis. While D. reflexa is able to develop large arborescent forms with conspicuous crowns by anomalous secondary growth, F. insignis remains relatively small and is only capable of primary growth. Biomechanical investigations were performed by applying vertical loads up to rupture to lateral branches of both species. This allows the analysis of the fracture mechanics and the determination of the maximal force, stress and strain at rupture as well as the fracture toughness. Functional morphology was correlated with the mechanical behaviour of these plants and compared to data of other dicotyledonous trees. The high energy absorption found in the rupture process of lateral branches of D. reflexa and F. insignis makes them promising biological concept generators with a high potential for biomimetic implementation, i.e., for the development of branched fibre-reinforced technical composites. A wide range of constructional elements with branched (sub-)structures can be optimised by using solutions inspired by plant ramifications, e.g., in automotive and aerospace engineering, architecture, sports equipment and prosthetic manufacturing.
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Standish, Jeffrey R., Suzette Sharpe, Shawn Butler, Lina M. Quesada-Ocampo, and Inga Meadows. "First Report of Downy Mildew, Caused by Peronospora effusa, on Spinach (Spinacia oleracea) in North Carolina." Plant Health Progress 21, no. 3 (January 1, 2020): 194–96. http://dx.doi.org/10.1094/php-04-20-0025-br.
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In this brief, we report the first observation of downy mildew caused by Peronospora effusa on spinach grown in North Carolina. To this end, we characterized the morphology of sporangiophores and sporangia, and compared the internal transcribed spacer region and cytochrome oxidase I sequences to confirm pathogen identity.
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Nagai, Satoshi, Jun Ohtani, Kazumi Fukazawa, and Jing Wu. "Sem Observations on Perforated Ray Cells." IAWA Journal 15, no. 3 (1994): 293–300. http://dx.doi.org/10.1163/22941932-90000611.
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The occurrence and morphology of perforated ray cells in eight Yunnan hardwoods were investigated using SEM, and the micromorphology of their perforation plates compared with those in the vessel member end walls. In most cases the perforation plates were dimorphic with the total area of the openings in the perforated ray cells sm aller than the perforation plates in the vessel member ends.
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Nicolás, Emilio, Trinitario Ferrandez, José Salvador Rubio, Juan José Alarcón, and Ma Jesús Sánchez-Blanco. "Annual Water Status, Development, and Flowering Patterns for Rosmarinus officinalis Plants Under Different Irrigation Conditions." HortScience 43, no. 5 (August 2008): 1580–85. http://dx.doi.org/10.21273/hortsci.43.5.1580.
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The annual water status and phenological patterns of Rosmarinus officinalis plants in relation to irrigation were studied to improve the use of this species in gardening conditions. Rosmarinus officinalis seedlings were pot-grown for 4 months in the nursery. After this period, plants were transplanted to field conditions before three irrigation treatments were applied from Nov. 2000 to Dec. 2001 (control and deficit treatments: C, T-1 and T-2, respectively). The total amount of water applied by irrigation during the experimental period was 167 mm for control, 83.5 mm for T1 (50% of the control), and 50 mm for T-2 (30% to the control). Two main periods of vegetative growth (beginning of spring and fall) were observed in all treatments. At the end of the experimental period, deficit irrigation had altered the morphology of the R. officinalis plants, reducing plant height and shoot growth. Maximum flowering intensity occurred at the beginning of fall for all irrigation treatments. Deficit irrigation treatments induced a more intense flowering density, although of lower longevity than control plants. The annual pattern of shoot water potential at predawn reflected the irrigation regimes, although less difference resulting from irrigation effect was detected in this parameter at midday. Plants under deficit irrigation showed a conservative strategy in the use of water, reducing stomatal conductance. This finding may be of use for the successful gardening of Rosmarinus officinalis plants in semiarid conditions.
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Nagaoka, Nobuyuki, Shoji Naoe, Yu Takano-Masuya, and Shoko Sakai. "Green greenhouse: leaf enclosure for fruit development of an androdioecious vine, Schizopepon bryoniifolius." Proceedings of the Royal Society B: Biological Sciences 287, no. 1936 (October 7, 2020): 20201718. http://dx.doi.org/10.1098/rspb.2020.1718.
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Individual plants can produce leaves that differ substantially in size, morphology and many other traits. However, leaves that play a specific role in reproduction have rarely been reported. Here, we report leaves specialized to enclose fruit clusters and enhance seed production in an annual vine, Schizopepon bryoniifolius . Enclosure leaves were produced at the end of the growing season in late autumn. They were different in greenness and structure from other leaves. Under solar radiation, the ambient temperature inside an intact enclosure was up to 4.6°C higher than that near a fruit cluster whose enclosure leaves had been removed. We found that enclosures were thicker at colder sites. Removal of enclosing leaves negatively affected fruit survival and/or growth, but we could not identify the exact mechanism. The results suggested that enclosures allow the plant to produce seeds under the cold weather the plant encounters at the end of its life. Vegetative and reproductive traits of plants have usually been studied separately. This study indicates how they can dynamically interact, as shown by an examination of associations among leaf and reproductive trait changes according to life stages.
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Webster, Theodore M., and Timothy L. Grey. "Glyphosate-Resistant Palmer Amaranth (Amaranthus palmeri) Morphology, Growth, and Seed Production in Georgia." Weed Science 63, no. 1 (March 2015): 264–72. http://dx.doi.org/10.1614/ws-d-14-00051.1.
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Herbicide-resistant Palmer amaranth has become the most economically detrimental weed of cotton in the southeast United States. With the continual marginalization of potential herbicide tools, research has expanded to include alternative means of affecting future Palmer amaranth populations by altering safe sites and reducing inputs to the seedbank population. The influence of delayed Palmer amaranth establishment on seed production potential has not been investigated in the southeast United States. Studies were conducted to evaluate the influence of time of Palmer amaranth establishment on morphology, growth, and seed production. The experiment was a factorial, with five levels of Palmer amaranth transplanting (0 to 12 wk after cotton planting) and two levels of crop type (cotton and noncrop). In the absence of crop competition, the first cohort of Palmer amaranth produced 446,000 seeds per plant. This potential seed production was reduced 50% when Palmer amaranth plants were established nearly 6 wk later. In contrast, the first Palmer amaranth cohort growing in competition with cotton produced 312,000 seeds, 30% less than was produced in the absence of competition. Interference from cotton shifted time to 50% seed production to nearly 4 wk earlier in the growing season, relative to plants without crop competition. Delayed establishment of Palmer amaranth simulates premature loss of herbicide efficacy and alters the competitive balance between cotton and Palmer amaranth. Although the planting time that resulted in 50% reduction in Palmer amaranth plant height at the end of the season was not affected by the presence of cotton, 50% reduction in plant width and biomass occurred within the first 3.8 wk of the growing season when growing with cotton, more than 4 wk earlier than Palmer amaranth growing without a crop. This suggests that early season weed control programs will have a large effect on Palmer amaranth potential growth and seed production, as well as crop yield. To implement soil seedbank reduction strategies effectively, information on mechanisms that regulate Palmer amaranth persistence in the soil seedbank is needed.